Anyway, what would I gain by trying an XX78 Super Slam in 2315 but yet fletched with a 5" feather instead of a 4" vane? ....one of the never ending curiosities with archery.
If what you are shooting works good, probably nothing
XX78's are more bend resistant, but shoot the same as XX75's. I shoot them in mixed lots frequently, with no difference. As for trying feathers, read all the above.